i18n routes with CakePHP 1.3

Internationalizing a CakePHP application can be tricky when it comes to deal with i18n urls. We will see in this article how the Custom route classes introduced by CakePHP 1.3 could be used to add the current language to your urls in a few lines of code.
EDIT: This proof of concept has now been improved and a better version of the code below can be found in CakeDC's I18n plugin on Github
Requ...